Transducer mounting assembly

ABSTRACT

A transducer mounting assembly having a plurality of magnetic transducers each with its own gap. Each gap is independently adjustable laterally relative to the gaps of the other transducers and further adjustable to position all gaps transversely of the record path and in a single straight line extending through all gaps.

179/1002 CA .346/74 MC .340/l74.1 F

[ Mar. 14, 1972 Pettus........................... Lubkin etChristoffi.,........

ABSTRACT 7 Claims, 7 Drawing Figures Elite tates Fates ()lah et al.

388 555 999 lull 7 1 1 [54] TRANSDUCER MGUNTING ASSEMBLY [72] Inventors:Louis Olah, Cupertino; Gregory J.

Maleski, Sunnyvale. both of Califv [73] Assignee: Newell Industries,lnc., Sunnyvale, Calif.

Primary Examiner-Stanley M. Urynowicz, Jr. Assistant Examiner-Alfredl-lv Eddlcman [22] Filed: July 10, 1969 Attorney Flehr, Hohbach, Test,Albritton & Herbert [21] Appl.No.:

A transducer mounting assembly having a plurality of magnetictransducers each with its own gap Each gap is independently adjustablelaterally relative to the gaps of the other transducers and furtheradjustable to position all gaps transversely of the record path and in asingle straight line extending through all gaps.

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TRANSDUCER MOUNTING ASSEMBLY BACKGROUND OF THE INVENTION This inventionpertains to a magnetic transducer mounting assembly for properlydisposing the recording gap of a magnetic recording transducer relativeto a moving record medium, and is particularly useful in providingpositional adjustment of the several gaps in multiple gap transducerassemblies, as where they are located in side-by-side relation.

Heretofore, for example, in a number of magnetic recording machines,transducers have been disposed in side-by-side relationship forcooperation with respective recording channels or paths extending alongthe direction of movement of the recording medium.

In certain machines, the record medium, such as magnetic recording tape,may be fed in either of two opposite directions and the transducers arearranged to cooperate with different paths during the playing of thetape in one direction from those paths with which the transducers weredisposed to cooperate while moving the tape in its original direction.Under these circumstances, problems of misaligned recording gaps,previously capable of being tolerated, may become suiticiently severe asto constitute a limitation upon the usefulness of the equipment.

For example, where a number of transducer gaps are arranged inside-by-side relation, it is desirable and usually intended that all ofthe gaps of the multiple transducer assembly lie in a common lineextending normal to the direction of travel of the magnetic medium.However, considering the extremely small dimensions involved in mostmachines, such alignment is quite difficult to achieve in manufacturingmultiple gap transducer elements, particularly where each magneticrecording transducer forms a separate structure independently removablefrom the assembly for purposes of replacement for example.

Thus, a problem referred to as gap scatter arises where the gap of oneor more of the side-by-side transducers does not lie in a direct linewith the others. While this problem is not particularly serious forextremely minor variations of positioning of the gap, the problembecomes regenerative and is enhanced to a considerable degree wherebidirectional movement of the recording medium is employed together withlateral shifting of the head assembly between reversals of the medium.

In addition to the above, it is typically highly desirable to insureuniform spacing between the record paths. Where multiple transducers aremanufactured and assembled individually into an assembly (for purposesof allowing any individual transducer to be replaced upon detection ofits defective operation or function) it has been observed that preciseuniform interchannel spacing has not been readily achievable.

In addition to the above, where a plurality of recording transducers aredisposed in a common support assembly, the gaps of each of thetransducers should be arranged to confront the record medium from acommon plane. This requirement also has presented problems in the past.

Yet another problem which has existed in the construction of multipletransducer mounting assemblies is to be found in the problem of insuringthat all of the transducer gaps are oriented at right angles to thedirection of movement of the recording medium. This correction isreferred to herein as a correction in the azimuth of the transducer.Thus, it will be apparent that where one or more of the transducer gapsis twisted slightly relative to its proper orientation perpendicular tothe path of movement of the medium, problems are immediately createdwhich are well known to those skilled in the art.

SUMMARY OF THE INVENTION AND OBJECTS In general, it is an object of thepresent invention to provide an improved transducer mounting assembly.

It is another object of the invention to provide an improved transducermounting assembly which readily and simply provides a solution to theabove problems and technical shortcomings heretofore experienced.

It is yet a further object of the invention to provide an improvedtransducer mounting assembly wherein a number of magnetic recording orplayback transducers may be supported in readily removable relationshipwith respect to each other and yet provide correction for each of theabove conditions.

In general, there has been provided a transducer assembly of a type forsupporting a plurality of magnetic transducers for transducing recordpaths along a moving record medium wherein each transducer includes arecording or playback gap extending transversely of the path, usuallyperpendicular to the path. A plurality of individual mounting assembliesare joined together each including its own frame element for supportingan associated one of the transducers. Means are provided with respect toeach transducer for independently adjusting the position of the gapthereof laterally relative to the gaps of the other transducers. Meansare further provided for each transducer for independently adjusting theposition of each gap to move the gap relative to its own frame so as'tolocate all gaps in a single straight line extending transversely of therecord path. All of the individual transducer assemblies are heldtogether to form a multiple gap assembly whereby the above advantageousadjustments can be readily made at minimal cost.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an isometric view partiallybroken away showing a multiple head transducer assembly, according tothe invention;

FIG. 2 shows a diagram for use in describing a problem known as gapscatter;

FIG. 3 is a side elevation view showing a transducer assembly, accordingto the invention;

FIG. 4 shows an enlarged detail section view taken along the line 4-4 ofFIG. 3;

FIG. 5 is a side elevation view of a unitary component of the assemblyas shown in FIG. 3;

FIG. 6 shows a section view of FIG. 5 taken along the line 66 thereof;

FIG. 7 is a plan view of FIG. 5.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The multiple gaptransducer assembly 10 shown in FIG. I, and its individual componenttransducer mounting assemblies 11, are capable of accommodatingadjustments to position their respective magnetic recording gaps 12whereby (a) the lateral spacing between gaps can be uniformlyestablished, (b) the gaps can all be placed upon a common straight lineaxis 13 (FIG. 2) oriented perpendicular to the direction 14 of amagnetic recording path, and (c) each gap 12 can further beindependently rotated to place it in precise parallelism with thestraight line axis 13 so as to make any needed azimuth corrections, asnow to be described.

As shown in FIG. 1, the multiple gap transducer assembly 10 includes aplurality of four individual component mounting assemblies 11 which areidentical in construction, one of which will be described in detailfurther below.

The stack of four individual component mounting assemblies 11 lie incoplanar relation to form a group held together by dowel pins 16. Theconsolidated group of units 11 is then fastened by suitable means, suchas the screws 17 threaded into holes 19 formed in a flat face of anysuitable mounting stirrup or bracket 13. As shown herein, bracket 18includes a registration face portion 18a against which assembly 10 canbe properly registered as to provide easy alignment of the attachmentopenings 21 through which screws 17 are disposed.

Referring now to FIG. 3 and to the mounting element shown in FIG. 5, thefunction and operation of the individual component mounting assemblies11 can be more readily understood. FIG. 2 diagrams certain of thecorrectional adjustments in the gap positioning for referencehereinafter.

Thus, assembly 11 carries a magnetic recording or playback transducerfor cooperating with (transducing) a moving magnetic record medium so asto record or play back signals along a record path extending in thedirection opposite to the direction of movement of the medium relativeto the transducing gap 12.

As will be readily understood by those skilled in this technology,magnetic transducer assemblies 2th of a type for recording or playingback signals with respect to a moving magnetic recording medium commonlyemploy a ring-type magnetic core element 21 which forms a magnetic fluxcircuit from one pole piece portion 21a to the other, 21b. A coil 22 ofwire, as schematically shown in FIG. 3 encircles a portion of themagnetic core element 21 whereby upon properly energizing the coil 22, asufficient magnetic flux can be generated at gap l2 so as to record thiselectrical event on that portion of the magnetic record medium thenpassing beneath gap 12. During playback, recorded signals appearing atgap 12 serve to complete the magnetic flux circuit through core element21 whereby a coil, such as coil 22 can serve to sense the presence ofthese prerecorded signals and feed the output of the coil to suitablecircuitry for utilization.

As shown in FIG. 3, leads 23, 24 are shown coupled to output cables 26,27 for transmitting or receiving the signals referred to above.

Each assembly 11 includes a frame unit 23 of a rigid material, such asbrass, formed in a planar configuration whereby its opposite side faces28a, 28b lie in parallel, spaced planes so that a stack of such units 11can be registered in side-by-side relation as explained above (HS. 1).

As shown in FIG. 5, each frame 28 is formed as an integral structurewherein the material remains temperature stable and is ductile andpermanently deformable when subjected to stress so as ideally not tohave any memory characteristic or resilience. A suitable material forthese components may, for example, be brass.

Each frame unit 28 includes means for carrying a magnetic transducerassembly at the distal end of a downwardly depending tab 29 formed withan opening 31 adapted to accommodate the coil portion of transducerassembly 20. lm mediately above tab 29, a wrench block 32 has beenformed whereby a suitable wrench or other engaging tool can be insertedinto the access passages 33 to engage and twist block 32 (and tab 29)about axis 34. In this manner, a gap l2 can be twisted into atransversely extending perpendicular orientation relative to pathdirection M in the plane of the recording surface.

Thus, means are provided for supporting transducer assembly 20 and tab29 from a mounting axis 36 disposed to extend in the direction of therecord path 14. The relatively thin bridge portions 36a are sufficientlysmall whereby upon engaging and twisting block 32, slight permanentlydeformed changes in the bridge portions 36a can be effected.

Means are provided herein for adjusting the lateral position of each gap12 to provide uniform spacing between recording paths, as now to bedescribed. Thus, as shown in FIG. 6, block 32 is offset laterally to oneside of the mounting axis 36 whereby a screw 37, such as an Allen screw,can be threaded into contact against the upper contact surface of theblock to rotate block 32 (and tab 29 with transducer 20) about axis 36.Accordingly, such rotation of the downwardly depending tab 29 carriestransducer 20 laterally to one side so as to diminish the spacingbetween adjacent transducer gaps i2. Portions of unit 28, such as block32, tab 29 and portions yet to be described, clear of and between planesof the opposite faces 28a, 28b of unit 28 whereby the adjustingmovements described herein may be accommodated.

Means are provided for moving the position of gap i2 relative to frame28 in a direction along path 14 so that all gaps 12 can be brought intoa common transversely extending axis 13 (FIG. 2). In this manner, theproblem of gap scatter (shown by gaps l2, l2", l2', l2' in H6. 2) can becorrected.

Thus, there is provided means supporting transducer 20 and forming anelongated support arm 39. Support arm 39 is movable about an axistransversely thereto by threading screws 41 downwardly through the uppertransverse portion of frame unit 28 into contact against the uppersurface of support arm 39. Support arm 39 is carried within theperiphery of frame unit 28 by the relatively thin and weakened bridgeportions 39a which are perforated for passing electrical cable 26, 27therethrough from transducer 20.

Accordingly, if it is desired to shift gap 12 to the left as shown inFIGS. 3 or 5, the right-hand screw 43 is screwed further downwardly soas to bend the right-hand end of support arm 39 very slightly about theleft-hand weakened bridge portion 39a. In order to move gap 12 to theright as shown in FIG. 3, the reverse procedure is, of course, pursued.

In order to advance any given gap 12 outwardly toward the record medium,both screws 41 are advanced together. i.e., an equal amount, and in thismanner all gaps 12 can be disposed to lie in a common plane forpresentation to the surface of the record medium.

Briefly, it will be readily evident that a structure of the typedescribed above can be readily adjusted so as to orient and dispose thegaps 12 as desired to correct for any imperfections, however slight, intheir disposition.

Thus, if it is necessary to move gap 12 one direction or the other inthe direction of the recording path so as to bring the gap into a commontransverse axis 13, one or the other of the two screws 41 can beemployed to act upon support arm 39 and bend it downwardly from one endor the other. This action serves to move the cantilevered structurecomprised of tab 29 and transducer 20 to position the gap 12.

Where it is desired to correct for lack of uniformity between adjacentgaps 12, the gaps can be moved from one side to the other by means ofoperation of screw 37 acting downwardly against the top of block 32 soas to rotate tab 29 to one side.

In the event that gap 12 of any given unit 1 l is oriented with anincorrect azimuth characteristic, it becomes a simple matter to engagethe wrench flats" formed by the flat sides of the wrench block 32 andtwist this structure slightly to deform the relatively thin bridges 36aconstituting part of the axis 36.

We claim:

1. In a transducer assembly of a type for supporting a magnetictransducer to cooperate with a record medium moving in a predetermineddirection to record or play back signals along a record path extendingalong said medium in said direction, and wherein said transducerincludes a recording or playback gap defined between transducer polepiece portions, the gap extending transversely of the record path, amounting assembly comprising a frame, a bridge portion defining amounting axis extending in a direction generally parallel to said recordpath, a support arm carrying said transducer and extending from saidbridge portion in a direction nonnal to said axis, said support armbeing movable about an axis normal to said mounting axis for adjustingthe angle of said gap relative to said path, threaded means carried bysaid bridge portion and engaging said support arm for rotating said armabout said mounting axis to move said gap laterally of said path, andthreaded means carried by said frame and engaging said bridge portionfor moving said bridge portion and said mounting axis relative to saidframe.

2. A transducer assembly according to claim 1 wherein said frame, bridgeportion, and support arm are formed as a unitary structure from ductile,permanently deformable material.

3. A transducer assembly according to claim I wherein the threaded meanscarried by said frame includes a pair of adjusting screws engaging saidbridge portion on opposite sides of said support arms.

4. In a transducer assembly of a type for supporting a plurality ofmagnetic transducers to cooperate with a record medium moving in apredetermined direction to transduce signals along a record pathextending along said medium in said direction, and wherein saidtransducers each include a recording or playback gap defined betweentransducer pole piece portions, the gaps extending transversely of therecord path, a plurality of mounting assemblies each comprising aplanar, rigid frame for carrying one of said transducers, a bridgeportion defining a mounting axis extending in a 5. In a transducerassembly of a type for supporting a plurality of magnetic transducersfor transducing record paths along a moving record medium and whereineach transducer includes a recording or playback gap extendingtransversely of the path, a mounting assembly comprising a plurality ofplanar frame elements for respectively supporting said transducers, eachof said frame elements including a generally U-shaped outer portiondefining a generally rectangular opening, a support member disposed insaid opening, and extending in a direction generally parallel to saidpaths, ductile ear portions connecting the ends of said member to thesides of said outer portion, a support arm carrying one of thetransducers and extending from said support member in a direction normalthereto, and a pair of ductile ear portions connecting said support armto said support member, and means for holding all of

1. In a transducer assembly of a type for supporting a magnetictransducer to cooperate with a record medium moving in a predetermineddirection to record or play back signals along a record path extendingalong said medium in said direction, and wherein said transducerincludes a recording or playback gap defined between transducer polepiece portions, the gap extending transversely of the record path, amounting assembly comprising a frame, a bridge portion defining amounting axis extending in a direction generally parallel to said recordpath, a support arm carrying said transducer and extending from saidbridge portion in a direction normal to said axis, said support armbeing movable aBout an axis normal to said mounting axis for adjustingthe angle of said gap relative to said path, threaded means carried bysaid bridge portion and engaging said support arm for rotating said armabout said mounting axis to move said gap laterally of said path, andthreaded means carried by said frame and engaging said bridge portionfor moving said bridge portion and said mounting axis relative to saidframe.
 2. A transducer assembly according to claim 1 wherein said frame,bridge portion, and support arm are formed as a unitary structure fromductile, permanently deformable material.
 3. A transducer assemblyaccording to claim 1 wherein the threaded means carried by said frameincludes a pair of adjusting screws engaging said bridge portion onopposite sides of said support arms.
 4. In a transducer assembly of atype for supporting a plurality of magnetic transducers to cooperatewith a record medium moving in a predetermined direction to transducesignals along a record path extending along said medium in saiddirection, and wherein said transducers each include a recording orplayback gap defined between transducer pole piece portions, the gapsextending transversely of the record path, a plurality of mountingassemblies each comprising a planar, rigid frame for carrying one ofsaid transducers, a bridge portion defining a mounting axis extending ina direction generally parallel to said record path, a support armcarrying said transducer and extending from said axis in a directionnormal thereto said support arm being movable about an axis normal tosaid mounting axis, threaded means carried by said bridge portion forrotating said support arm about mounting axis, and threaded meanscarried by said frame and engaging said bridge portion for moving saidbridge portion and said mounting axis relative to said frame.
 5. In atransducer assembly of a type for supporting a plurality of magnetictransducers for transducing record paths along a moving record mediumand wherein each transducer includes a recording or playback gapextending transversely of the path, a mounting assembly comprising aplurality of planar frame elements for respectively supporting saidtransducers, each of said frame elements including a generally U-shapedouter portion defining a generally rectangular opening, a support memberdisposed in said opening and extending in a direction generally parallelto said paths, ductile ear portions connecting the ends of said memberto the sides of said outer portion, a support arm carrying one of thetransducers and extending from said support member in a direction normalthereto, and a pair of ductile ear portions connecting said support armto said support member, and means for holding all of said frame elementstogether.
 6. A transducer assembly according to claim 5 wherein each ofsaid frame elements further includes an adjusting screw carried by saidsupport member and engaging said support arm for rotating said arm aboutan axis generally parallel to said paths.
 7. A transducer assemblyaccording to claim 5 wherein each of said frame elements furtherincludes a pair of adjusting screws carried by the outer portion of saidelements and engaging said support member proximate to the ends thereof.